The present invention relates to a mill in which work rolls are crossed each other to provide a high strip crown control capability for strips, and more particularly to a work rolls crossing type mill which can lubricate between back-up rolls and work rolls, a rolling system incorporating at least one such mill, and a rolling method.
As one of work rolls crossing type mills, JP, A, 47-27159 discloses a mill in which only work rolls are crossed each other.
There is also known, as described in Mitsubishi Heavy Industries Technical Report Vol. 21, No. 6, a mill in which a pair of an upper work roll and an upper back-up roll and a pair of a lower work roll and a lower back-up roll are each built into a one-piece roll set and arranged such that axes of the pair rolls (roll sets) are crossed with respect to each other.
Additionally, there are known 4-high work rolls crossing mills in which a lubricant is applied for the purpose of reducing thrust forces produced between work rolls in a roll kissed condition after strips have passed the work rolls, as disclosed in JP, A, 3-234305; an ordinary 4-high work rolls uncrossing mill in which a coolant is applied to work rolls and back-up rolls in a casing provided on the strip entrance side, and a lubricant as rolling oil is separately supplied to between the work rolls and a strip, as disclosed in JP, A, 61-7009; and a mill in which a lubricant as rolling oil is supplied only when a strip is in contact with rolls, as disclosed in JP, A, 47-27849.